Why does it matter, you know that none of the readings make any sense whatsoever. He is obviously searching in the dark.
even if I'm completely satisfied with physical layout of your amp ( it's always nice to see detailed and carefully produced gadget ) , it's obviously time that someone skilled take care of finishing that amp ;
it's clear that you don't have basic knowledge in electronic , you can't learn that in few day's time , and messing with mains powered equipment is dangerous , when you don't have enough knowledge ;
even if you are careful with mains area of amp , it's easy to make mistake if you became frustrated wandering ... .
but relax - even Rome isn't built in one day .
it's clear that you don't have basic knowledge in electronic , you can't learn that in few day's time , and messing with mains powered equipment is dangerous , when you don't have enough knowledge ;
even if you are careful with mains area of amp , it's easy to make mistake if you became frustrated wandering ... .
but relax - even Rome isn't built in one day .
Your measurements show that your technique is off. If you have 37VDC (or were you measuring AC?) on the rails you cannot have 45V rail to rail and there is no way you can have 52V on the output.
A while back we suggested that you:
You must not have followed the steps properly if your PSU is acting the way it is. Initially you had 7.65V output offset, now it is 52.5? Disconnect the amp from the PSU and go back to step one.
When you get to measuring DC voltages, measure with the black lead of your meter clipped to the common ground (that bus bar between the caps) - Do not move it. You might want to add a step 6a - connect your meter to the DC terminals of the bridges, power up with the bulb tester and verify that you have DC there. It will be lower than you would expect, but as long as it is ~2/3 of the AC voltage you are fine. Power down. go to step 7.
After step 8 you will need to bleed off the charge on the caps before connecting up your amp. Something like a 3k7 1W resistor across each rail will do. It will take a while to discharge. You can mount these before powering up on step 8, they will get too hot to touch. You can also make up a bleeder from several resistors of lower power rating. 3-4 ea. 10K 1/4W would do for temporary use.
Report back your readings: If you get something strange, STOP and report what you have done to that point and the readings.
AC voltage on each unloaded winding
AC voltage on each winding with a bridge connected
DC voltage across each bridge before connecting caps
Step 8 AC voltages across bridges
DC voltage ground to + rail
DC voltage ground to - rail
It would also help if you post pictures of the meter connection for each measurement, so that we are sure that you are measuring the proper voltage. This may require a bit of disassembly to get clear pictures.
Are the caps in the negative side of the filter bank connected properly (positive terminal to ground?)?
Once we are sure that your PSU is properly sorted, we'll take a look at the amp operation.
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Another thought - When measuring the rail voltages in step 8, measure at the caps before and after the inductors.
Also, measure both rail voltages at 1 minute and 2 minutes after you shut down AC power.
Also, measure both rail voltages at 1 minute and 2 minutes after you shut down AC power.
I'll have to agree with what the guys said. Get someone trained/skilled to help you if you don't feel comfortable working with mains voltage. Then rework the PSU, check transformer, caps and the resulting voltages, then proceed to the audio circuit.
Attached you'll find what I intended to post earlier.
Attached you'll find what I intended to post earlier.
Attachments
are you sure you wired the bridges right?
you got +52.5V spk- to V-. there you want -50V.
you get -5.72V spk- to V+. there you want +50V.
chek that you did not wire bridge V- to caps V+ or the other way, on one of the bridges.
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Don't worry about this, that was when I started taken measurements and the secondaries were mix up, already fixed.
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Left Pair 38.2 vac nothing connected. Are they close enough? Can I do next step?
Trans secondaries are rated 37 vac.
Trans secondaries are rated 37 vac.
OK.
Which two of the four wires that connect to the plus and minus terminals are connected to the neutral (ground) of the filter section?
Which two of the four wires that connect to the plus and minus terminals are connected to the neutral (ground) of the filter section?
While you're at it, trace all four wires to their filter connections and label them with what they go to. We don't know if the colors of them mean anything so we are going to ignore the colors of the wires.
Yes I do, this is what I have, but going to changed it to + and - of each pairs.
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Ahh - one wire from each bridge connects to the GROUND bus bar. Which ones? (hint - you gave the wrong answer above.)
Connect the one wire from each bridge to the bus bar, clip the black lead of your meter to the ground bar and measure the DC voltage to the unconnected bridge terminals. You should get a + and - voltage again.
Notice in your psu plan that one bank of caps connects the negative terminal to the ground bus and the other connects the positive terminal to ground. Verify the you have them connected that way.
Connect the one wire from each bridge to the bus bar, clip the black lead of your meter to the ground bar and measure the DC voltage to the unconnected bridge terminals. You should get a + and - voltage again.
Notice in your psu plan that one bank of caps connects the negative terminal to the ground bus and the other connects the positive terminal to ground. Verify the you have them connected that way.
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